FIG. 1 depicts a schematic diagram of telecommunications system 100 in the prior art. Telecommunications system 100 comprises:
i. network telecommunications terminal 101,
ii. telecommunications networks 102 and 107,
iii. primary data-processing system 103,
iv. near telecommunications terminals 104-1 through 104-J,
v. auxiliary data-processing system 105, and
vi. far telecommunications terminals 106-1 through 106-K;
all of which are interconnected as shown. The parameters J and K are positive integers.
The telecommunications terminals of system 100 are devices that are capable of originating and receiving calls, as well as exchanging signals (e.g., voice, data, etc.) with other telecommunications terminals. There are three categories of telecommunications terminals in telecommunications system 100: near telecommunications terminals, far telecommunications terminals, and network telecommunications terminals.
Near telecommunications terminal 104-j, wherein j is a value between 1 and J, inclusive, is a telecommunications terminal that is associated with primary data-processing system 103. Near terminal 104-j is capable of originating and receiving calls, as well as exchanging signals (e.g., control, voice, data, etc.) with other telecommunications terminals via primary data-processing system 103.
Far telecommunications terminal 106-k, wherein k is a value between 1 and K, inclusive, is a telecommunications terminal that is associated with auxiliary data-processing system 105. Far terminal 106-k is capable of originating and receiving calls, as well as exchanging signals (e.g., control, voice, data, etc.) with other telecommunications terminals through auxiliary data-processing system 105.
Network telecommunications terminal 101 is a telecommunications terminal that is associated with telecommunications network 102. Network terminal 101 is capable of originating and receiving calls, as well as exchanging signals (e.g., control, voice, data, etc.) with other telecommunications terminals via network 102.
Telecommunications network 102 provides telecommunications service for one or more network-associated telecommunications terminals, such as network terminal 101, and enables the terminals to communicate with one or more of near terminals 104-1 through 104-J and far terminals 106-1 through 106-K. Network 107 enables telecommunications service between systems 103 and 105 via trunks or other transmission pathways. Telecommunications network 102 or 107 might comprise part or all of the Public Switched Telephone Network (PSTN), part or all of a packet data network, a combination of different types of networks, and so forth. One or more switches, routers, transmission paths, or other telecommunications-enabling devices constitute networks 102 and 107.
Primary data-processing system 103 is a private branch exchange that directly serves and controls near terminals 104-1 through 104-J. Primary system 103 is capable of handling incoming calls (e.g., from terminal 101, etc.) from telecommunications network 102 via one or more transmission lines (e.g., Integrated Services Digital Network trunks, etc.). Primary system 103 forwards each incoming call to a target telecommunications terminal. If the target terminal is associated (e.g., registered, etc.) with primary system 103, then the terminal receiving the call is one of near terminals 104-1 through 104-J. If the target terminal is associated with auxiliary data-processing system 105, then the terminal receiving the call is one of far terminals 106-1 through 106-K. Primary system 103 is also capable of handling calls from near terminals 104-1 through 104-J and far terminals 106-1 through 106-K, and forwarding those calls to one or more other terminals in telecommunications system 100.
Auxiliary data-processing system 105 is a communications server that directly serves and controls far terminals 106-1 through 106-K. Auxiliary system 105 is capable of handling incoming calls (e.g., from network terminal 101, from near terminal 104-j, etc.) to far terminals 106-1 through 106-K. Auxiliary system 105 is also capable of handling outgoing calls from far terminals 106-1 through 106-K to other terminals in telecommunications system 100 via primary data-processing system 103.
With respect to the relationship between primary data-processing system 103 and auxiliary data-processing system 105, a call that is placed to a telephone number associated with primary system 103 is routed to primary system 103, but might then be mapped by primary system 103 to: (i) a near terminal 104-j, (ii) a far terminal 106-k, or (iii) both a near terminal 104-j and a far terminal 106-k. For example, primary system 103 might direct an incoming call via a trunk though network 107 and auxiliary system 105 to a far terminal 106-k. In the example, the directed-to terminal, far terminal 106-k, might be a Session Initiation Protocol-based phone and auxiliary system 105 might be co-located with primary system 103, as part of an enterprise telecommunications system. Alternatively, far terminal 106-k might be a cell phone and auxiliary system 105 might be a distant wireless switching center. Auxiliary system 105 operates asynchronously with respect to primary system 103.
During the setup of a telecommunications call, primary system 103 transmits a ringback signal to the calling terminal (e.g., network terminal 101, etc.), where the calling party hears the signal as a ringback tone. The ringback tone is used to inform the calling party that the called terminal is ringing or otherwise alerting the called party of the call. In North America, for example, the ringback tone is “on” for one second and “off” for three seconds, in repetition. The ringback signal is produced not by the calling party's switch, but by the terminating switch, such as primary system 103.
In a first call-handling scenario, a calling party at network telecommunications terminal 101 calls a telephone number that is associated with primary data-processing system 103. Telecommunications network 102 routes the call to primary system 103, which is the terminating system of the call. If the telephone number is associated with a particular deskset or other type of terminal that is directly served and controlled by primary system 103 (i.e., near telecommunications terminal 104-j), the associated terminal is instructed directly by primary system 103 to alert the terminal's user of the call. As the terminating system of the call, primary system 103 also transmits a ringback signal to the calling terminal to inform the calling party that the called terminal is ringing. Because the called terminal is directly served and controlled by primary system 103, system 103 is able to transmit the ringback signal with the certainty that the called terminal has, in fact, received an indication of the call and is alerting its user.
In a second call-handling scenario, the called telephone number, although still associated with primary system 103, is not associated with a terminal that is directly served and controlled by primary system 103. For example, the caller might have called a telephone number does not correspond to a specific, physical terminal associated with primary system 103. Instead, the telephone number might map to a group of terminals (i.e., a subgroup of far telecommunications terminals 106-1 through 106-K) associated with auxiliary data-processing system 105, such as a customer support phone bank. As a result, primary system 103 directs the call over to auxiliary system 105. As the terminating system of the call, primary system 103 transmits a ringback signal to the calling terminal in this second scenario as well. However, because auxiliary data-processing system 105 is a different system than primary data-processing system 103, a response to the directing of the call might not be received by primary system 103 until after ringback is transmitted to the calling terminal. A technique is needed to improve how an incoming call is handled across multiple data-processing systems at the terminating end of the call.